The development of wireless telecommunications has enabled the provision of mobile application services to vehicles by mobile application service providers such as OnStar.RTM.. Call-in service for Global Positioning System (GPS) determined vehicle location or directions to a desired vehicle destination, tracking of stolen vehicles, automatic notification of supplemental inflatable restraint (SIR) activation with dispatch of emergency services, and notification of a vehicle security system violation are examples of the mobile application services now available to properly equipped vehicles; and such mobile application services have provided improved convenience and security to vehicle operators.
Vehicles receiving such services are equipped with a wireless telecommunication system having an embedded transceiver and an embedded antenna capable of exchanging voice and data transmissions with an external transceiver connected in a telecommunications network, such as e.g. a cellular telephone network. Such systems typically include a handset available as voice interface between the vehicle operator and the embedded transceiver but may, alternatively or additionally, include an embedded microphone and speaker for "hands-free" voice communication. The systems may also provide general dialing capability for personal telephone calls over a public switched telephone network. But all external communication, whether voice or data, is maintained through the embedded transceiver and embedded antenna; and general dialing capability is thus restricted to calls to or from the vehicle.
It is also well known for a vehicle operator to carry a personal, portable transceiver such as a portable cellular or PCS telephone for personal telephone calls. Many such telephones are small and easily portable in a pocket or purse, but they are not ideal for calls from a vehicle. They have low gain antennas which, when used in the vehicle, are hampered in transmission and reception by the surrounding vehicle structure. In transmission, they are further limited in range by a transmitter considerably less powerful than that of a (typically) 3 watt embedded cellular transceiver, due to the portable transceiver's small size and need for battery powered operation when removed from the vehicle. In areas of marginal signal strength, a vehicle operator might have to stop and exit the vehicle in order to place a personal call from such a portable transceiver.